Influence of Aromatization Reaction Conditions in the Presence of HZSM-5 Catalyst

The reaction conditions include temperature, weight hourly space velocity (WHSV), catalyst loading amount Ga and Si/Al, vapor, calcination temperature, soaking order, pretreatment, oxygen, and microwave heating method. The study introduces the influence of aromatization reaction conditions over HZSM-5 catalyst in detail. The proper temperature, low weight hourly space velocity (WHSV), modified HZSM-5, non-oxygen and microwave heating method are beneficial to the aromatization reaction.     

Zn-Ni/HZSM-5催化剂上微波辐射诱导正己烷芳构化

对微波辐射条件下，Zn-Ni/HZSM-5催化剂上正已烷的芳构化反应，考察了反应条件对反应性能的影响，并与常规加热下的反应性能进行了。结果表明，在微波加热条件下，在一定程度上提高反应温度可以获得明显的总芳烃收率和BTX收率，谱明显地改变BTX中各组分的相对选择性；但随着反应时间的延长，反应性能的波动比常规加热时大。对微波辐射诱导催化反应的作用机理也进行了探讨。     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Abstract

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75–120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^?1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

The Conversion of Syngas to Liquid Fuels in a Dual-Bed Single Reactor Process

The effects of HZSM-5 temperature and weight hourly space velocity (WHSV) on conversion of syngas to liquid fuels were investigated in a single reactor process. The temperature of FT catalyst was constant (463 K), whereas the temperature of HZSM-5 varied (523, 573, 623 K). The value of WHSV ranged between 16 and 24 h^?1. HZSM-5 addition suppressed the formation of CH₄ and remarkably enhanced the formation of iso-C₅-C₁₂ paraffins. An increase of HZSM-5 temperature resulted in an enhancement of gaseous hydrocarbons, C₁₈₊ paraffins, and olefins. The optimal HZSM-5 temperature and WHSV were identified as 523 K and 16 h^?1, respectively.     

反应条件对HZSM-5基催化剂芳构化反应的研究进展

从温度、空速、催化剂、氧气和微波加热等方面,详细地论述了反应条件对HZSM-5基催化剂芳构化反应,认为适当的温度、低空速、改性HZSM-5、无氧和微波加热等条件对芳构化反应是有利的。     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75-120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^-1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

Aromatization of n-Hexane Under Microwave Irradiation

Abstract

The aromatization of n-hexane over HZSM-5 and ZnNi/HZSM-5 catalysts has been investigated using two different heating methods: microwave irradiation (MW) and conventional heating (CH). The results indicate that the aromatics and BTX yields under MW are higher than those under CH. n-Hexane aromatization mechanism under MW was similar to that under CH at the temperature below 673 K. However, the mechanism of n-hexane aromatization was different at the temperature from 673 K to 753 K. The higher the reaction temperature is, the more condensed-nucli aromatics are produced. Therefore, MW requires the lower reaction temperature when equal yields of aromatics and BTX are obtained.     

The Aromatization Properties of Nano-HZSM-5 Catalyst

Abstract

In this article, the influence of reaction conditions on the aromatization over nano-HZSM-5 zeolite catalyst was investigated. The experimental results showed that nano-HZSM-5 catalyst has the best aromatization properties under the optimal conditions: reaction temperature 430°C, reaction pressure 0.3 MPa, and liquid hourly space velocity 1 h^?1. At the optimal operational conditions, the conversion of olefins in the feedstock was 76.15%. Aromatics yield and the content of olefins, content of aromatics, and content of isoparaffins in liquid product were up to 84.98%, 12.11%, 39.58%, and 35.23%, respectively.     

Ga改性HZSM-5催化剂芳构化性能的考察

以不同温度水热处理的纳米HZSM-5为母体制备了Ga/HZSM-5催化剂,并对该催化剂在FCC汽油芳构化上的性能进行考察。结果表明：以600 oC水热处理、硝酸洗涤的HZSM-5为母体制备的Ga/HZSM-5（GaHS600）的芳构化性能最优,当温度为480 oC,WHSV为1 h-1时,GaHS600上所得产品中芳烃和（C3+C4）体积分数分别为58.3%和7.6%。在本实验考察条件下,金属二次改性对Ga/HZSM-5芳构化性能的提高并无有利影响。     

An Orthogonal Method for Aromatization Reactions of Shenghua FCC Gasoline

Abstract

Using a confined fluidized bed reactor and aromatization catalysts (LBO-A and LBO-16), the aromatization performance of Shenghua fluid catalytic cracking (FCC) gasoline has been studied in an orthogonal method. The experimental results reveal that the optimum reaction condition for the light oil yield was reaction temperature 420°C, WHSV 40 h^?1, mass ratio catalyst to oil 4 and 75% LBO-A and 25% LBO-16; the optimum reaction condition for aromatics amount in the light oil was reaction temperature 420°C, WHSV 30 h^?1, mass ratio catalyst to oil 5 and 65% LBO-A and 35% LBO-16, the olefin content is remarkably reduced from about 54.7% to 12.8% and 8.7% (by mass), respectively, at the same time the reaction mechanism of aromatization reaction is put forward based on the experimental result.     

液化石油气在ZnNi/HZSM-5催化剂上的芳构化

用浸渍法制备ZnNi/HZSM -5催化剂 ,通过对液化石油气的芳构化试验表明 ,其活性明显高于HZSM -5催化剂。在常压、温度 540℃、质量空速 1h- 1条件下 ,芳烃和苯 -甲苯 -二甲苯 (BTX)混合物收率分别达到 4 8%和4 5%左右 ,液态产品中芳烃质量分数高达 98%。同时还考察再生活化温度、再生活化时间和反应温度对芳构化催化作用的影响。结果表明 ,再生活化温度对催化剂的恢复影响比较大 ,只有达到 575℃ ,活化时间至少 2h ,催化剂活性才能完全恢复 ;低温段 ( 550℃ )再生活化时 ,再生活化时间将影响催化剂活性 ;反应温度在 50 0～ 550℃时 ,随着反应温度增加 ,液体收率和芳烃收率随之增加 ,对芳烃选择性影响不大 ,BTX收率幅度波动较大。用金属改性的ZnNi/HZSM -5催化剂具有较强的芳构化能力。     

催化裂化汽油馏分在P—Zn／HZSM-5催化剂上的芳构化

以50～100℃的FCC汽油馏分为原料,在连续固定床反应器上考察了工艺条件对P-Zn／HZSM-5催化剂在芳构化反应中性能的影响。结果表明,在反应温度410℃、反应压力0．5MPa、液时空速1．0h^-1的操作条件下,液相产物中的烯烃、异构烷烃和芳烃的含量分别为8．56％,13．07％,73．39％。催化剂P-Zn／HZSM-5具有较好的芳构化降烯烃效果。     

正戊烷芳构化生成丙烷反应路径及其工艺条件

选取3种不同硅/铝摩尔比的HZSM-5分子筛为正戊烷芳构化反应的催化剂,并对硅/铝摩尔比为90的分子筛进行锌改性制备改性催化剂,对几种催化剂进行吡啶-红外表征和NH3程序升温脱附表征,考察了正戊烷在各催化剂上的芳构化反应性能。结果表明：正戊烷主要在催化剂表面B酸中心上发生质子化裂解和氢转移反应生成丙烷,锌改性HZSM-5催化剂表面B酸量减少,不利于提高丙烷收率;在温度为420 ℃、进料质量空速为0.5 h-1、反应压力为0.5 MPa的条件下,正戊烷在硅/铝摩尔比为30的HZSM-5催化剂上反应可以得到57.57%的丙烷和11.95%的芳烃收率。     

改性HZSM-5催化剂用于MTP反应的研究

考察了不同硅铝比的HZSM-5催化剂和磷、镁或铈改性的HZSM-5催化剂在甲醇制丙烯(MTP)反应中的催化性能。研究了在Mg-HZSM-5和Ce-HZSM-5的催化作用下,反应温度、液时空速、进料组成对MTP反应的影响。确定较佳的反应条件为:温度为380℃～400℃,WHSV在5 h-1左右,纯甲醇进料。在此条件下,Ce-HZSM-5的丙烯产率达55%。     

The Relationship Between the Conversion of a C5 Fraction and Reaction Conditions

Catalytic reaction of a C5 fraction has been studied by using a C5 fraction as raw material and big hole cationic exchanger resin D115 as catalyst, and curve equations of a C5 fraction have been put forward on the basis of the conversion under different reactive conditions, such as temperature, molecule ratio, and weight hourly space velocity (WHSV). A mathematical method is first introduced to study on the relationship between the conversion of C5 fraction and the different reactive conditions. The results from experimental data are in accordance with the quantitatively analytical conclusions drawn from the calculated data.     

Transformation of Cycloparaffin over Zeolite-Supported Metal Catalyst for Improving the Octane Number of Gasoline

Abstract

In order to improve the octane number of gasoline, Ni/HZSM-5 and NiMo/HZSM-5 catalysts were prepared by impregnation method, and their activities for hydrocracking, hydroisomerization, and aromatization were investigated by the transformation of cylcohexane. The experimental results show that the conversion of cyclohexane is affected greatly by the reaction temperature. The production of methyl-cyclopentane is the result of the hydroisomerization of cyclohexane. The olefin distribution reveals that the hydrocracking reaction of cyclohexane over acidic zeolite catalyst probably obeys the dimolecular mechanism and the C₅ and C₇ olefins come from the cracking of the dimer of cyclohexane. The activities of the presulfided Ni/HZSM-5 and NiMo/HZSM-5 catalyst for the transformation of cyclohexane were evaluated and the product selectivities for two presulfided catalysts are similar to those obtained over reduced Ni/HZSM-5 catalyst.     

丁烷芳构化反应规律的研究

利用100 mL等温固定床实验装置,采用LAC芳构化催化剂,研究了丁烷芳构化生产芳烃的反应规律,主要考察了反应温度和空速对丁烷芳构化产品分布的影响。实验结果表明,高温和低空速可得到较高的液体收率和芳烃收率。随着反应温度的升高,丁烷芳构化反应的液体收率逐渐增大,同时干气产率也增加较快;随着进料空速的增大,丁烷芳构化反应的液体收率和干气收率逐渐减小,而液化石油气收率逐渐增大。反应温度和进料空速对n-C4H10的芳构化反应影响较大,而对i-C4H10的影响较小;i-C4H10较n-C4H10易转化为芳烃,当反应温度为460～540℃、质量空速为0.25～1.00 h-1时,以n-C4H10为原料能得到质量分数为17%～30%的轻质芳烃和质量分数为10%～16%的液化石油气,以i-C4H10为原料能得到质量分数为33%～41%的轻质芳烃和质量分数为21%～34%的液化石油气。在大量实验的基础上得到了丁烷单体烃芳构化反应的液体收率随工艺条件变化的经验关联式,利用此关联式在一定条件下可以预测不同组成丁烷芳构化反应的液体收率,关联式的绝对误差小于2.5%。     

SiO_2改性HZSM-5催化剂催化C_4烯烃裂解生产丙烯

利用硅油对HZSM-5分子筛进行液相沉积S iO2改性,制备了S iO2/HZSM-5催化剂(简称催化剂);考察了S iO2沉积量及反应条件对催化剂催化C4烯烃裂解生产丙烯性能的影响;采用X射线衍射、N2等温吸附-脱附、透射电子显微镜、扫描电子显微镜、吡啶吸附-脱附红外光谱等方法对催化剂进行了表征。实验结果表明,在HZSM-5分子筛上沉积SiO2调变了催化剂的孔结构和酸性,SiO2沉积量影响催化剂的性能,当SiO2沉积量为7.0%(质量分数)时,催化剂具有适当的孔结构和酸性,催化剂的性能较好。在530℃、0.1MPa、原料重时空速2.0 h-1、催化剂中SiO2沉积量7.0%的条件下,C4烯烃转化率为42.9%,丙烯收率为28.3%。     

碳酸二乙酯与邻苯二酚乙基化反应合成邻羟基苯乙醚

以Cr2O3/Al2O3为催化剂、碳酸二乙酯(DEC)为乙基化试剂,邻苯二酚在气相连续流动固定床反应器内进行乙基化反应合成了邻羟基苯乙醚;考察了反应温度、空速、原料配比等条件对催化剂活性的影响,同时考察了催化剂的稳定性。实验结果表明,Cr2O3负载量(质量分数)为21%的Cr2O3/Al2O3催化剂对该反应具有较好的催化活性;适宜的反应条件为:反应温度603K,重时空速1.5h-1,n(DEC)∶n(邻苯二酚)=4.0,在此条件下反应7h,邻苯二酚转化率高达100.0%,目的产物邻羟基苯乙醚的选择性最大为83.02%。升高反应温度有利于反应的进行,但反应温度过高会导致副产物的增加。催化剂的稳定性实验结果表明,在20h内催化剂的活性稳定,之后目的产物选择性逐渐降低,副产物苯环的碳烷基化产物的含量逐渐增加。     

低温合成HZSM-5分子筛上甲醇制丙烯反应性能

分别在不同温度下(180℃和120℃)水热合成了HZSM-5分子筛,并采用x射线衍射、扫描电子显微镜、N2低温物理吸附方法对分子筛进行了表征。表征结果显示,低温合成的分子筛晶粒较小,表面粗糙且有微晶晶粒;其比表面积、孔容和孔直径均较高温合成样品大。在常压、440℃以及甲醇质量空速为4.0h-1反应条件下,在固定床反应器上考察了HZSM-5分子筛的甲醇制丙烯(MTP)反应性能。评价结果表明,低温合成的HZSM-5分子筛用于MTP反应具有高的丙烯选择性(45.85%)和丙烯/乙烯质量比(4.08)。